"This letter will hopefully send a signal to BOP that they need to re-evaluate staff cuts and prioritize the safety of correctional officers, particularly in facilities with our most violent offenders," said Rep. Thomas A. Marino, R-Lycoming, the coalition leader.

Dangerous staffing levels contribute to incidents of violence, he contends, citing 256 acts of violence in the last fiscal year at Canaan.

The letter, which Sens. Bob Casey and Pat Toomey have signed, states in January there were 25 acts of violence at Canaan, where another 15 positions are to be cut besides the 39 that have already.

In 2013, corrections officer Eric Williams was murdered while working alone in a housing unit with more than 100 inmates, the lawmakers point out.

In 2015, then BOP director Charles E. Sammuels Jr. testified before Congress the inmate to staff ratio was 4.4 to 1. The ratio today is 8.3 to 1, a level the letter states "is unsafe for staff and should immediately be corrected."

The positions being eliminated are vacant because of a January 2017 hiring freeze. The letter notes the hiring freeze has been lifted for all Justice Department agencies except the BOP.

Other House members who signed the letter are Lou Barletta, Matthew Cartwright, Brian Fitzpatrick, Mike Kelly, Keith Rothfus and Glen "GT" Thompson.